Class 11th CBSE CS Subjective

Class 11th CBSE CS

Subjective

Corrected Python Code

1. Mehak, a Python programmer, wants to print the squares of all odd
numbers between 1 and 20. She wrote the following code, but it
contains errors. Correct the code and underline the corrections made.

num = 1
while num < 20
 if num % 2 = 1
  print(num*2)
 num += 1

num = 1
while num < 20:
    if num % 2 == 1:
        print(num**2)
    num += 1

Python Program - Positive, Negative or Zero

2.Write a program in Python that takes a number as an input from the user and check whether that number is positive, negative, or zero.

# Program to check whether a number is positive, negative, or zero

num = float(input("Enter a number: "))

if num > 0:
    print("The number is Positive")
elif num < 0:
    print("The number is Negative")
else:
    print("The number is Zero")

Python Expression Evaluation

3.What will be the output of following statement: (9 >= 8) and (not False) or (7 < 3)

(9 >= 8) and (not False) or (7 < 3)

Step 1: Evaluate Relational Operators

9 >= 8  → True
7 < 3   → False

True and (not False) or False

Step 2: Evaluate NOT Operator

not False → True

True and True or False

Step 3: Apply Operator Precedence (not → and → or)

True and True → True
True or False → True

Final Output

True

Python Expression Evaluation

4. What will be the output of following statement: 232 + 10 - 2

2**3**2 + 10 - 2

Step 1: Operator Precedence

Exponentiation (**) → Right to Left
Addition (+) and Subtraction (-) → Left to Right

Step 2: Evaluate Exponentiation

2**3**2
= 2**(3**2)

3**2 = 9
2**9 = 512

Step 3: Perform Addition and Subtraction

512 + 10 = 522
522 - 2  = 520

Final Output

520

Difference Between System Software and Application Software

5. Difference Between System Software and Application Software

Basis of Comparison	System Software	Application Software
Definition	Software that manages and controls computer hardware and provides a platform for other software.	Software designed to perform specific tasks for the user.
Purpose	To operate and control the computer system.	To help users perform particular tasks like writing, calculating, designing, etc.
Dependency	Essential for the functioning of the computer.	Depends on system software to run.
User Interaction	Works in the background; limited direct user interaction.	Directly interacts with the user.
Installation	Usually pre-installed with the operating system.	Installed as per user requirement.
Examples	Operating Systems, Device Drivers, Utility Programs	MS Word, Excel, Photoshop, Web Browsers

Nested Loop Output in Python

6. Output of Nested Loop Program

Given Code:

for i in range(2,5):
    for j in range(1,i+1):
        print(j,end="")
    print()

Step 1: Values of i

range(2,5) → 2, 3, 4

Step 2: Loop Execution

When i = 2 → 12
When i = 3 → 123
When i = 4 → 1234

Final Output:

12
123
1234

Divisibility Check Program

7.Python Program: Check Divisibility by 3 and 5

Program Code:

# Program to check whether a number is divisible by both 3 and 5

num = int(input("Enter an integer: "))

if num % 3 == 0 and num % 5 == 0:
    print("The number is divisible by both 3 and 5.")
else:
    print("The number is NOT divisible by both 3 and 5.")

Explanation:

int(input()) takes integer input from the user.
num % 3 == 0 checks divisibility by 3.
num % 5 == 0 checks divisibility by 5.
The and operator ensures both conditions are true.

Example Runs:

Enter an integer: 15
The number is divisible by both 3 and 5.

Enter an integer: 9
The number is NOT divisible by both 3 and 5.

Multiplication Table Program

8. Python Program: Print Multiplication Table

Program Code:

# Program to print the multiplication table of a number

num = int(input("Enter an integer: "))

print(f"\nMultiplication Table of {num}:\n")

for i in range(1, 11):
    print(f"{num} x {i} = {num * i}")

Explanation:

int(input()) takes integer input from the user.
range(1, 11) generates numbers from 1 to 10.
The loop multiplies the number with values from 1 to 10.
Formatted strings (f-strings) are used for clean output.

Example Output:

Enter an integer: 5

Multiplication Table of 5:

5 x 1 = 5
5 x 2 = 10
5 x 3 = 15
5 x 4 = 20
5 x 5 = 25
5 x 6 = 30
5 x 7 = 35
5 x 8 = 40
5 x 9 = 45
5 x 10 = 50

Hexadecimal to Binary Conversion

9. Find the Binary Equivalent of (FACE)₁₆

Step 1: Convert Each Hex Digit to 4-bit Binary

Hex	Binary
F	1111
A	1010
C	1100
E	1110

Step 2: Combine the Binary Values

F     A     C     E
1111  1010  1100  1110

Final Answer

(FACE)₁₆ = (1111101011001110)₂

String Processing Program

Corrected Python Program

Ravi, a student of class XI has created the following code, help him by writing the correct code in
the space given in the following coding:
Line = "Kendriya Vidyalaya Jagdalpur:1564"
Length = ____________ # code for line1
print("Total no of characters are :", Length)
cnt = 0
for j in Line:
 if j._________________ : # code for line2
 cnt += 1
print("Total no of digits in given Line are", ________) # code for line3
print(Line.____________) # code for line4
print("KV Code :", Line[_______]) # code for line5

Line = "Kendriya Vidyalaya Jagdalpur:1564"

Length = len(Line)                 # code for line1
print("Total no of characters are :", Length)

cnt = 0
for j in Line:
    if j.isdigit():                # code for line2
        cnt += 1

print("Total no of digits in given Line are", cnt)   # code for line3

print(Line.upper())                # code for line4

print("KV Code :", Line[-4:])      # code for line5

Output:

Total no of characters are : 34
Total no of digits in given Line are 4
KENDRIYA VIDYALAYA JAGDALPUR:1564
KV Code : 1564

Evaluation of Python Expressions

(a) 15 * (4 % 4) // 2 + 6

Step 1: 4 % 4 = 0
Expression becomes: 15 * 0 // 2 + 6

Step 2: 15 * 0 = 0
        0 // 2 = 0

Step 3: 0 + 6 = 6

Final Answer: 6

(b) not 10 > 5 and 2 < 11 or not 10 < 2

Step 1:
10 > 5  → True
2 < 11  → True
10 < 2  → False

Expression becomes:
not True and True or not False

Step 2:
not True  → False
not False → True

Expression becomes:
False and True or True

Step 3:
False and True → False
False or True  → True

Final Answer: True

Expansion of Computer Terms

EEPROM – Electrically Erasable Programmable Read-Only Memory
VDU – Visual Display Unit
LCD – Liquid Crystal Display
OMR – Optical Mark Recognition

Python Module and Math Functions

Module in Python and Math Module Functions

What is a Module in Python?

A module in Python is a file containing Python code (functions, variables, classes, etc.) that can be reused in other Python programs. It helps in code reusability, organization, and maintainability.

Example of Importing a Module:

import math

Two Functions of Math Module

1. math.sqrt(x)

Returns the square root of a number.

import math
print(math.sqrt(25))

Output: 5.0

2. math.factorial(x)

Returns the factorial of a non-negative integer.

import math
print(math.factorial(5))

Output: 120

Difference Between List and Tuple

Differences Between List and Tuple

Basis	List	Tuple
Mutability	Lists are mutable (elements can be changed).	Tuples are immutable (elements cannot be changed).
Syntax	Created using square brackets [ ]	Created using parentheses ( )

Example:

# List
my_list = [10, 20, 30]
my_list[0] = 100   # Allowed

# Tuple
my_tuple = (10, 20, 30)
my_tuple[0] = 100  # Error (Not Allowed)

Difference Between Virus and Worm

Differences Between Virus and Worm

Basis	Virus	Worm
Dependency	A virus requires a host file or program to attach itself and spread.	A worm is a standalone program and does not require a host file.
Mode of Spread	Spreads when the infected file or program is executed by the user.	Spreads automatically through networks without user action.

Summary

Virus → Needs a host file and user action to spread.

Worm → Self-contained and spreads automatically through networks.

Python Tokens

Tokens in Python

What are Tokens?

Tokens are the smallest individual units of a Python program. The Python interpreter breaks the source code into tokens for analysis and execution. They are the basic building blocks of Python syntax.

Types of Python Tokens

1. Keywords

Reserved words with predefined meaning.

if, else, while, for, True, False, None, def, class, return

2. Identifiers

Names given to variables, functions, classes, etc.

name = "Ravi"

3. Literals

Fixed values in a program.

Numeric: 10, 3.14
String: "Hello"
Boolean: True, False
None: None

4. Operators

Arithmetic: +, -, *, /, %
Relational: >, <, ==
Logical: and, or, not
Assignment: =, +=

5. Punctuators (Separators)

( ), [ ], { }, , , : , ; , .

Corrected Python Code

Corrected Python Code (Corrections Underlined)

Observe the following Python code very carefully and rewrite it after removing all errors with
each correction underlined.
Str = 'Jagdalpur'
L = length(Str)
For j in range(L)
Print(j)

Str = 'Jagdalpur'

L = len(Str)          # length() corrected to len()

for j in range(L):   # For → for and colon added

    print(j)           # Print → print

Corrections Made:

length(Str) → len(Str)
For → for (Python is case-sensitive)
Added missing colon (:) after for loop
Print → print (Python is case-sensitive)
Proper indentation added

List, Tuple and Dictionary in Python

1. Explain List in Python

A list is a built-in data structure in Python used to store multiple values in a single variable. It is written inside square brackets []. Lists are ordered and mutable, meaning their elements can be modified after creation.

numbers = [10, 20, 30, 40]
numbers.append(50)

Lists are widely used to store and manage related data items.

2. Explain Tuple in Python

A tuple is a collection data type written inside round brackets (). Like lists, tuples are ordered collections but they are immutable, meaning their values cannot be changed after creation.

data = (1, 2, 3)

Tuples are used when data should remain constant throughout the program.

3. Explain Dictionary in Python

A dictionary stores data in key–value pairs inside curly brackets {}. Each key is unique and used to access its corresponding value. Dictionaries are mutable.

student = {"name": "Riya", "roll": 12}

Dictionaries are useful for storing structured information.

4. Differentiate between List and Tuple

A list is mutable and written using square brackets. A tuple is immutable and written using round brackets. Lists are used when data changes frequently, while tuples are used for fixed data.

5. How are elements accessed in List and Tuple?

Elements are accessed using index numbers starting from 0. Negative indexing is also allowed.

fruits = ["Apple", "Mango", "Banana"]
print(fruits[0])

6. How are elements accessed in Dictionary?

Dictionary elements are accessed using keys instead of index numbers.

student = {"name": "Riya", "roll": 12}
print(student["name"])

7. Explain mutability in List and Dictionary

Lists and dictionaries are mutable, meaning their elements can be changed after creation.

numbers = [1, 2, 3]
numbers[1] = 5

student = {"name": "Riya"}
student["roll"] = 12

8. Explain immutability of Tuple

Tuples are immutable. Once created, their elements cannot be changed, added, or removed. Attempting to modify a tuple results in an error.

data = (10, 20, 30)

9. Explain slicing in List and Tuple

Slicing extracts a range of elements using the colon (:) operator.

nums = [10, 20, 30, 40, 50]
print(nums[1:4])

10. Main Characteristics of Dictionary

Stores data in key–value pairs
Keys must be unique
It is mutable
Does not use index numbers
Keys must be immutable data types
Values can be of any data type

Dictionaries are commonly used for structured data storage.

Definitions of Computer Terms

i. Application Software

Application software refers to programs designed to perform specific tasks for users. These tasks may include word processing, calculations, designing, browsing, etc. Examples include MS Word, Excel, web browsers, and media players.

ii. Cache Memory

Cache memory is a small, high-speed memory located inside or close to the CPU. It temporarily stores frequently used data and instructions to speed up processing and reduce access time to main memory (RAM).

iii. Language Processor

A language processor is system software that translates a program written in high-level or assembly language into machine language so that the computer can execute it.

Types of Language Processors:

Compiler
Interpreter
Assembler

Social Media - Class 11 CS 083

What is Social Media? Give examples of some social media platforms with their usage.

What is Social Media?

Social Media refers to online platforms and applications that allow people to create, share, and exchange information such as messages, images, and videos through the internet. It helps users communicate and interact with others across different locations.

Examples of Social Media Platforms with Their Usage

1. Facebook

Connecting with friends and relatives
Sharing photos and videos
Creating groups and pages
Promoting businesses

2. Instagram

Sharing pictures and short videos
Posting stories and reels
Following celebrities and influencers
Advertising products

3. WhatsApp

Sending text messages
Sharing documents and media files
Making voice and video calls
Creating group chats

4. YouTube

Watching educational and entertainment videos
Uploading and sharing videos
Learning through tutorials

5. LinkedIn

Professional networking
Searching for jobs
Sharing career-related information

Conclusion

Social media has become an important part of modern life. It helps people stay connected, share knowledge, promote businesses, and access information easily. It should always be used responsibly.

Identity Theft Prevention and Social Media

Three Methods to Prevent Identity Theft

1. Use Strong and Unique Passwords

Create passwords that are difficult to guess. A strong password should contain uppercase and lowercase letters, numbers, and special symbols. Use different passwords for different accounts.

Example: Use Riya@2026# instead of 123456.

2. Enable Two-Factor Authentication (2FA)

Two-factor authentication provides extra security. Even if someone knows your password, they cannot log in without a verification code sent to your phone or email.

Example: Receiving an OTP while logging into your email account.

3. Do Not Share Personal Information Online

Avoid sharing sensitive information such as bank details, passwords, OTPs, or ID numbers on social media or unknown websites.

Example: Never share your ATM PIN or OTP with anyone.

Python Program to Reverse a Number

Python Program to Reverse the Digits of a Number

Program Code:

num = int(input("Enter a number: "))
reverse = 0

while num > 0:
    digit = num % 10          # Extract last digit
    reverse = reverse * 10 + digit
    num = num // 10           # Remove last digit

print("Reversed number is:", reverse)

Python Program - Largest of Three Numbers

Python Program to Find the Largest of Three Numbers

Program Code:

# Program to find the largest of three numbers

num1 = float(input("Enter first number: "))
num2 = float(input("Enter second number: "))
num3 = float(input("Enter third number: "))

if num1 >= num2 and num1 >= num3:
    print("The largest number is:", num1)

elif num2 >= num1 and num2 >= num3:
    print("The largest number is:", num2)

else:
    print("The largest number is:", num3)

Operators in Python - Class 11 CS 083

Operators in Python

Definition of Operators

Operators in Python are special symbols used to perform operations on variables and values. They are used to perform calculations, comparisons, and logical decisions in a program.

Example: 5 + 3 → (+) is an operator.

Relational Operators

Relational operators are used to compare two values. The result is either True or False.

Operator	Meaning	Example	Result
==	Equal to	5 == 5	True
!=	Not equal to	5 != 3	True
>	Greater than	7 > 4	True
<	Less than	2 < 1	False
>=	Greater than or equal to	6 >= 6	True
<=	Less than or equal to	3 <= 5	True

Example Program:

a = 10
b = 20

print(a > b)
print(a != b)

Logical Operators

Logical operators are used to combine two or more conditions.

Operator	Meaning	Example	Result
and	True if both conditions are True	(5 > 2 and 6 > 3)	True
or	True if at least one condition is True	(5 > 10 or 6 > 3)	True
not	Reverses the result	not(5 > 2)	False

Example Program:

x = 15
y = 10

print(x > 5 and y > 5)
print(x < 5 or y > 5)
print(not(x > 5))

Characteristics of Dictionary - Class 11 CS 083

Characteristics of Dictionary in Python

Introduction

A dictionary in Python is a built-in data type used to store data in the form of key–value pairs. Each key is linked to a specific value, which helps in quick and easy access of data.

Main Characteristics

1. Stores Data in Key–Value Form

Each item in a dictionary consists of a key and its corresponding value.

student = {"name": "Riya", "roll": 12}

2. Keys Must Be Unique

No two keys can be the same. If repeated, the latest value replaces the old one.

data = {"a": 10, "a": 20}
print(data)

3. Mutable in Nature

A dictionary can be modified after creation. We can add, update, or delete items.

student["marks"] = 85

4. Unordered Collection

Items are not stored in a fixed sequence. Values are accessed using keys instead of index numbers.

5. Keys Can Be Different Data Types

Keys can be integers, strings, or tuples, but they must be immutable.

info = {1: "One", "city": "Surat"}

6. Values Can Be Any Data Type

Values in a dictionary can be numbers, strings, lists, or even another dictionary.

Python Program - Swap Without Third Variable

Python Program to Swap Two Numbers Without Using a Third Variable

Method 1: Using Arithmetic Operators

# Program to swap two numbers without using a third variable

num1 = int(input("Enter first number: "))
num2 = int(input("Enter second number: "))

print("Before swapping:")
print("num1 =", num1)
print("num2 =", num2)

num1 = num1 + num2
num2 = num1 - num2
num1 = num1 - num2

print("After swapping:")
print("num1 =", num1)
print("num2 =", num2)

Method 2: Using Multiple Assignment

# Program to swap two numbers without using a third variable

num1 = int(input("Enter first number: "))
num2 = int(input("Enter second number: "))

print("Before swapping:")
print("num1 =", num1)
print("num2 =", num2)

num1, num2 = num2, num1

print("After swapping:")
print("num1 =", num1)
print("num2 =", num2)

Explanation

The program accepts two numbers from the user.
It swaps the values without using any extra variable.
The first method uses arithmetic operations.
The second method uses Python’s multiple assignment feature.

10 Questions on List in Python - Class 11 CS 083

10 Questions with Answers on List in Python

1. What is a list in Python?

A list is a data type used to store multiple values in a single variable. The elements are written inside square brackets and separated by commas.

numbers = [10, 20, 30, 40]

2. How is a list different from a tuple?

A list is mutable, meaning its elements can be changed. A tuple is immutable, meaning its elements cannot be changed.

3. How do you access elements of a list?

Elements are accessed using index numbers starting from 0.

fruits = ["Apple", "Mango", "Banana"]
print(fruits[1])

4. What is negative indexing?

Negative indexing is used to access elements from the end of the list. -1 represents the last element.

print(fruits[-1])

5. How can you add elements to a list?

Elements can be added using append() or insert() methods.

numbers = [1, 2, 3]
numbers.append(4)

6. How can you remove elements from a list?

Elements can be removed using remove(), pop(), or del.

numbers.remove(2)

7. What is slicing in a list?

Slicing is used to access a range of elements using the colon operator.

nums = [10, 20, 30, 40, 50]
print(nums[1:4])

8. Can a list store different data types?

Yes, a list can store values of different data types.

data = [10, "Hello", 3.5]

9. How do you find the length of a list?

The len() function is used to find the number of elements.

numbers = [1, 2, 3, 4]
print(len(numbers))

10. How do you iterate through a list?

A for loop is used to traverse the elements of a list.

numbers = [1, 2, 3]
for n in numbers:
    print(n)

Blog Insights

September 1, 2026

Choosing the Best Digital Solution for Your Business Needs

September 1, 2026

How CodeManiac Studio Delivers Exceptional Digital Products

September 1, 2026

The Values and Culture Driving CodeManiac Studio’s Success

Class 11th CBSE CS Subjective